package sshpractice;

/* -*-mode:java; c-basic-offset:2; indent-tabs-mode:nil -*- */
/**
 * This program will demonstrate the user authentification by public key.
 *   $ CLASSPATH=.:../build javac UserAuthPubKey.java
 *   $ CLASSPATH=.:../build java UserAuthPubKey
 * You will be asked username, hostname, privatekey(id_dsa) and passphrase.
 * If everything works fine, you will get the shell prompt
 *
 */
import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;

public class UserAuthPubKey{
    public static void main(String[] arg){

        try{
            JSch jsch=new JSch();

            JFileChooser chooser = new JFileChooser();
            chooser.setDialogTitle("Choose your privatekey(ex. ~/.ssh/id_dsa)");
            chooser.setFileHidingEnabled(false);
            int returnVal = chooser.showOpenDialog(null);
            if(returnVal == JFileChooser.APPROVE_OPTION) {
                System.out.println("You chose "+
                        chooser.getSelectedFile().getAbsolutePath()+".");
                jsch.addIdentity(chooser.getSelectedFile().getAbsolutePath()
//			 , "passphrase"
                );
            }

            String host=null;
            if(arg.length>0){
                host=arg[0];
            }
            else{
                host=JOptionPane.showInputDialog("Enter username@hostname",
                        System.getProperty("user.name")+
                                "@localhost");
            }
            String user=host.substring(0, host.indexOf('@'));
            host=host.substring(host.indexOf('@')+1);

            Session session=jsch.getSession(user, host, 22);

            // username and passphrase will be given via UserInfo interface.
            UserInfo ui=new MyUserInfo();
            session.setUserInfo(ui);
            session.connect();

            Channel channel=session.openChannel("shell");

            channel.setInputStream(System.in);
            channel.setOutputStream(System.out);

            channel.connect();
        }
        catch(Exception e){
            System.out.println(e);
        }
    }


    public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
        public String getPassword(){ return null; }
        public boolean promptYesNo(String str){
            Object[] options={ "yes", "no" };
            int foo=JOptionPane.showOptionDialog(null,
                    str,
                    "Warning",
                    JOptionPane.DEFAULT_OPTION,
                    JOptionPane.WARNING_MESSAGE,
                    null, options, options[0]);
            return foo==0;
        }

        String passphrase;
        JTextField passphraseField=(JTextField)new JPasswordField(20);

        public String getPassphrase(){ return passphrase; }
        public boolean promptPassphrase(String message){
            Object[] ob={passphraseField};
            int result=
                    JOptionPane.showConfirmDialog(null, ob, message,
                            JOptionPane.OK_CANCEL_OPTION);
            if(result==JOptionPane.OK_OPTION){
                passphrase=passphraseField.getText();
                return true;
            }
            else{ return false; }
        }
        public boolean promptPassword(String message){ return true; }
        public void showMessage(String message){
            JOptionPane.showMessageDialog(null, message);
        }
        final GridBagConstraints gbc =
                new GridBagConstraints(0,0,1,1,1,1,
                        GridBagConstraints.NORTHWEST,
                        GridBagConstraints.NONE,
                        new Insets(0,0,0,0),0,0);
        private Container panel;
        public String[] promptKeyboardInteractive(String destination,
                                                  String name,
                                                  String instruction,
                                                  String[] prompt,
                                                  boolean[] echo){
            panel = new JPanel();
            panel.setLayout(new GridBagLayout());

            gbc.weightx = 1.0;
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            gbc.gridx = 0;
            panel.add(new JLabel(instruction), gbc);
            gbc.gridy++;

            gbc.gridwidth = GridBagConstraints.RELATIVE;

            JTextField[] texts=new JTextField[prompt.length];
            for(int i=0; i<prompt.length; i++){
                gbc.fill = GridBagConstraints.NONE;
                gbc.gridx = 0;
                gbc.weightx = 1;
                panel.add(new JLabel(prompt[i]),gbc);

                gbc.gridx = 1;
                gbc.fill = GridBagConstraints.HORIZONTAL;
                gbc.weighty = 1;
                if(echo[i]){
                    texts[i]=new JTextField(20);
                }
                else{
                    texts[i]=new JPasswordField(20);
                }
                panel.add(texts[i], gbc);
                gbc.gridy++;
            }

            if(JOptionPane.showConfirmDialog(null, panel,
                    destination+": "+name,
                    JOptionPane.OK_CANCEL_OPTION,
                    JOptionPane.QUESTION_MESSAGE)
                    ==JOptionPane.OK_OPTION){
                String[] response=new String[prompt.length];
                for(int i=0; i<prompt.length; i++){
                    response[i]=texts[i].getText();
                }
                return response;
            }
            else{
                return null;  // cancel
            }
        }
    }
}